Product Description:

B&R Automation manufactures the 7AI351.7 for its System 2003 Controllers series. This plug-in module provides a single differential analog input that sends precise voltage or current data to the CPU section of the controller rack, allowing machine-level programs to monitor process sensors in real time. By occupying one slot in the backplane, the unit expands the controller’s analog measurement capability without requiring external signal conditioners. Its role is to bring low-level process signals into the control system in a format that can be evaluated directly by the application program.

The converter inside the module digitizes incoming signals with a resolution of 12-bit + sign. Because the input is differential, common-mode disturbances are canceled, but there is no channel isolation, so the reference potential must be shared with the controller ground. An active filter uses a cutoff frequency of 1 kHz and rolls off at 60 dB per decade to suppress higher-frequency noise before conversion. The front end presents an impedance of 20 MΩ, which minimizes sensor loading, and the electronics are housed in an enclosure rated IP20 for finger-safe operation inside a protected cabinet. The module provides one input channel, uses an INT output format that is compatible with the controller’s integer math, and keeps gain error within 0.1% of the final value.

A static current offset accuracy of ±5 µA and a voltage offset accuracy of ±2.5 mV help the module maintain repeatable zero points, while linearity error remains within 0.05 % of final value across the full span. The onboard potentiometer supply delivers ±9.94 V for bridge or slide-wire transducers, and that source includes short-circuit protection. During measurement mode, the unit draws only 0.3 W from the backplane, which helps limit thermal rise in densely populated racks. These operating values make the module suitable for motion axes, temperature loops, and other analog feedback tasks used with the System 2003 platform.